domain-->folder

[uiawebmaster]

Hi, couldn't find the right section to post in so here's my question:

I have a website working in http://abc.com/folder/
Now I have new domain def.com and I want it to point to this website.
As I understand something should be adjusted in htaccess. But I don't know the right format because I'm not very good in regular expressions.
Can you please help me?

[Fang]

http://httpd.apache.org/docs/1.3/mod/mod_alias.html#redirectperm
The .htaccess on abc.com would contain:Redirect permanent / http://www.def.com/